Floorboard and floor convering for resilient floor

ABSTRACT

A floorboard for making a resilient floor by joining to at least one neighbouring, substantially identical floorboard ( 1 ′), so that joined upper neighbouring parts ( 7, 7 ′) of the edge portions of the floorboards ( 1, 1 ′) together define a joint plane (F), perpendicular to the main plane (P) of the joined floorboards, comprises a resilient base (10) which is arranged on the underside of the floorboard ( 1, 1 ′) and which extends beyond said joint plane (F), supporting layer (1 1) which is arranged between the underside of the floorboard ( 1 ) and the resilient base ( 10 ), and a locking system, which is arranged along at least two parallel edges ( 25   a,    25   b;    26   a,    26   b ) of the floorboard ( 1 ) and integrated with the floorboard, for mechanical joining, vertically (D 1 ) and horizontally (D 2 ), of the floorboard ( 1 ) to the neighbouring, substantially identical floorboard ( 1 ′). Furthermore, a kit of parts and a method for installation of resilient floors as well as a method for manufacturing resilient floors are disclosed.

FIELD OF THE INVENTION

The present invention relates to floorboards for making a resilient orenergy-absorbing floor, i.e. a flooring for sports or other activities.

BACKGROUND ART

The term “sports floor” relates to resilient floorings that exhibitsufficient resilience, bouncing effect or impact-absorbing capability tobe suited for sports activities, dancing or other activities where aflooring that is kind to the users is desired.

There are mainly three categories of sports floor: i) point-elasticfloors which consist of an elastic soft layer (i.e. a carpet) which isglued immediately to a hard base; ii) surface-elastic floors whichconsist of a comparatively flexurally rigid upper layer of assembledfloorboards resting on a resilient carpet or on joists or spacer blockswhich in turn rest on the base; and iii) combined constructionsinvolving a carpet and joists or spacer blocks.

Category ii) includes, inter alia, U.S. Pat. No. 4,819,932 whichdiscloses a sports floor where solid floorboards, which are joinedmechanically, are laid on a subfloor consisting of a large resilientbase which gives the floor resilient properties. Category ii) alsoincludes DE 860 40 04 U1, which discloses a sports floor wherefloorboards, which are joined mechanically, are laid on a subfloorconsisting of a resilient base made up of a plurality of adjoiningboards. The boards constituting the resilient base are laid so thattheir joints do not coincide with the joints of the floorboards.

One type of sports floor of category iii) is shown, for instance, inU.S. Pat. No. 5,778,621, where an upper layer of floorboards rests on acarpet, which in turn rests on resilient joists arranged on the base.

Furthermore U.S. Pat. No. 6,044,606 discloses a sports floor whereresilient pads are arranged on the upper side of the subfloor.

EP 0 455 616 discloses a sports floor where a resilient material isarranged in grooves in the underside of the floorboards. Moreover, thefloorboards shown in EP 0 455 616 are intended to be glued together toform a floor.

A frequent type of floorboards consists of a core and also a surfacelayer and a balancing layer. The core often consists of wood or woodfibre-containing material, such as MDF (Medium Density Fibreboard), HDF(High Density Fibreboard), particle board or plywood. The surface layermay be, for example, a thin hard decorative layer as found on so-calledlaminate floors. Alternatively, the surface layer may consist of wood orveneer, which can be treated to withstand wear, moisture etc: and whichcan be so thick as to allow regrinding of the floor. The function of thebalancing layer is to prevent the floor from bending when exposed to,for instance, moisture or variations in temperature.

As shown in WO 94/26999, the floorboard can also be provided with alower layer, such as a sound-absorbing layer for impact soundinsulation. However, this layer should not be elastic since it should becapable of taking up irregularities of the base.

With a view to joining two or more floorboards to form a flooring, aplurality of different systems for mechanical joining of floorboards areknown. Examples of such systems are shown in U.S. Pat. No. 4,426,820,DE-121 11 75, DE-198 51 200 C1, FR-267 51 74, WO 99/66151, WO 97/47834,JP 3169967, WO 96/27721, GB 143 04 23 and in WO 02/55809. Also U.S. Pat.No. 4,819,932 discloses a system for mechanical joining of floorboardsalong their long sides.

The above-mentioned sports floors, however, suffer from severaldrawbacks. One is that they are complex and consist of a large number ofdifferent parts that are to be assembled. This can take a relativelylong time, which results in a high cost of installation. Anotherdrawback is that they often take up a large space in the verticaldirection. A plurality of the known sports floors are also difficult todisassemble, for instance when they are to be moved or in connectionwith repair and exchange of individual floorboards.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a floorboard which withmaintained strength wholly or partly eliminates the above problems.

The object is achieved by means of a floorboard, a resilient floor, akit of parts and methods according to the independent claims.Embodiments of the invention will appear from the dependent claims andalso from the following description.

According to a first aspect of the invention, a floorboard is thusprovided for making a resilient floor by joining to at least oneneighbouring, substantially identical floorboard, so that joined upperneighbouring parts of the edge portions of the floorboards togetherdefine a joint plane, perpendicular to the main plane of the joinedfloorboards. The floorboard is characterised by a resilient base whichis arranged on the underside of the floorboard and which extends beyondsaid joint plane, a supporting layer which is arranged between theunderside of the floorboard and the resilient base, and a lockingsystem, which is arranged along at least two parallel edges of thefloorboard and integrated with the floorboard, for mechanical joining,vertically and horizontally, of the floorboard to the neighbouring,substantially identical floorboard.

By “resilient base” is meant an elastic material that is capable ofabsorbing and emitting energy, i.e. that has a resilient function.According to one embodiment, the resilient base can have a greaterthickness than the floorboard. The composition of materials, thethickness as well as the extent of the resilient base under thefloorboard can be varied for the purpose of adjusting the floorboard todifferent applications, such as different types of sport.

By the resilient base being “arranged” is meant that the resilient baseis fixedly arranged on the floorboard. According to one embodiment, theresilient base is already arranged on the floorboard at the factorywhere the floorboard is manufactured.

With a floorboard of this type, a resilient floor can be providedpractically as easily and quickly as a traditional parquet floor sincethe floorboards are complete when leaving the factory. Moreover, a smalloverall height is obtained since no complicated systems of joists arerequired.

By “edge portions” are meant portions along the edges of the floorboard.The “upper neighbouring parts” can, but need not, be in contact witheach other when two floorboards are in a joined state. Furthermore theycan have a very small vertical extent and be positioned anywhere in theupper part of the joint edge portion of the floorboard. According to oneembodiment, the “neighbouring parts” can be the verge of the surfacelayer of the respective floorboards.

By the resilient base being arranged on the underside of the floorboard,the floorboard can quickly and easily be laid and taken up, whichreduces the cost of installation.

By the resilient base extending beyond the joint plane, the resilientbase will be offset relative to the joint between the floorboards, whichincreases the strength of the sports floor.

According to one embodiment, the resilient base is arranged so that,with the floorboards in a joined state, it extends at least partly underthe neighbouring, substantially identical floorboard. By one and thesame resilient base supporting the floorboard on which it is arrangedand also the neighbouring floorboard, the two floorboards will move tothe same extent in the vertical direction when subjected to load,thereby increasing the strength in the joint.

According to another embodiment, the floorboard comprises a supportinglayer, which is arranged between the underside of the floorboard and theresilient base. The supporting layer reduces the load applied to themechanical locking system, especially when a mechanical locking systemhas been selected.

The supporting layer can have a greater modulus of elasticity than theresilient base. Materials that can be used for the supporting layercomprise, but are not limited to, MDF, HDF, plywood, particle board,wood material, plastic material or metal, such as aluminium. By thesupporting layer being made more rigid than the resilient base, the loadapplied to the mechanical locking system will be reduced.

The horizontal extent of the supporting layer can be smaller than ahorizontal extent of the floorboard. By “horizontal extent” is meant theextent in a direction which is perpendicular to the edge portion andparallel to the surface of the floorboard. The horizontal extent of thesupporting layer can be less than half the horizontal extent of thefloorboard perpendicular to the joint plane.

The floorboard can along at least two parallel edges comprise a lockingsystem integrated with the floorboard and intended for mechanicaljoining, vertically and horizontally, of the floorboard to theneighbouring, substantially identical floorboard.

By the locking system being “integrated” is meant that it isfactory-mounted on the floorboard, or alternatively formed in one piecewith the body of the floorboard.

With a mechanical locking system, a high surface finish is achieved bythe locking system ensuring the fit of the joints. Moreover it will be aquick operation to install floorboards with a mechanical locking system.They can also be taken up to be used in a different location, or toreplace individual floorboards that have been damaged.

The resilient base can extend beyond an outer part of the locking systemof the floorboard. By the resilient base extending beyond an outer partof the locking system of the floorboard, the strength is furtherincreased.

According to a second aspect, the invention provides a flooring forresilient floors, which comprises floorboards of the type as describedabove.

According to a third aspect, the invention provides a kit of parts formaking a resilient floor. The kit is characterised by a floorboard forjoining to a neighbouring, substantially identical floorboard, so thatjoined upper neighbouring parts of the edge portions of the floorboardstogether define a joint plane, which is perpendicular to the main planeof the joined floorboards, and a resilient base, which in terms of shapeand size is adapted to be arranged on the underside of the floorboard,so that the resilient base extends beyond said joint plane, and asupporting layer, which in terms of size and shape is adapted to bearranged between said floorboard and said resilient base, the floorboardalong at least two parallel edges being provided with a locking systemintegrated with the floorboard, for mechanical joining, vertically andhorizontally, of the floorboard to the neighbouring, substantiallyidentical floorboard.

The resilient base can be cut and, thus, adapted in advance to thefloorboard in terms of size and shape. Alternatively, the resilient basecan be delivered non-cut, for instance on a roll. According to thisaspect, the resilient base can be mounted on the floorboard before or inconnection with installation of the floorboard.

According to a fourth aspect, the invention provides a method for makinga resilient floor by joining a floorboard to a neighbouring,substantially identical floorboard, so that joined upper neighbouringparts of the edge portions of the floorboards together define a jointplane, which is perpendicular to the main plane of the joinedfloorboards. The method is characterised by joining the floorboards sothat a resilient base and a supporting layer, which are arranged on theunderside of the floorboard, extend beyond said joint plane, saidjoining comprising mechanical joining, vertically and horizontally, ofthe floorboard to the neighbouring, substantially identical floorboard.

The method is a quick and simple way of installing a resilient floor onan existing base.

According to a fifth aspect, the invention provides a method formanufacturing a floorboard for making a resilient floor. The method ischaracterised by providing a floorboard, which is designed for joiningto a neighbouring, substantially identical floorboard, so that joinedupper neighbouring parts of the edge portions of the floorboardstogether define a joint plane, which is perpendicular to the main planeof the joined floorboards, arranging on the underside of the floorboarda resilient base, which extends beyond said joint plane, arranging asupporting layer between said floorboard and said resilient base, andarranging along at least two parallel edges of the floorboard a lockingsystem integrated with the floorboard, for mechanical joining,vertically and horizontally, of the floorboard to the neighbouring,substantially identical floorboard.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail with reference to theaccompanying schematic drawings, which show examples of embodiments ofthe invention.

FIGS. 1 a and 1 b are schematic cross-sectional views of two edges,provided with a mechanical locking system, of two neighbouringfloorboards 1, 1′, which are provided with a resilient base 10 accordingto a first embodiment of the invention.

FIGS. 2 a and 2 b are schematic cross-sectional views of two edges;provided with a-mechanical locking system, of two neighbouringfloorboards 1, 1′, which are provided with a resilient base 10 and/or asupporting layer according to a second embodiment of the invention.

FIGS. 3 a-3 c illustrate a floorboard with a mechanical locking system,a resilient base and a supporting layer according to a third embodimentof the invention.

FIGS. 4 a-4 c show different ways of arranging the resilient base 10, 10a, 10 b, 10 c and/or the supporting layer 11, 11 a, 11 b, 11 c on theunderside of a floorboard 1, 1′.

FIG. 5 shows further ways of arranging the resilient base 10, 10 a, 10b, 10 c and/or the supporting layer 11, 11 a, 11 b, 11 c on theunderside of a floorboard 1, 1′.

FIG. 6 shows another way of arranging the resilient base 10 b, 10 cand/or the supporting layer 11 b, 11 c on the underside of a floorboard.

DESCRIPTION OF EMBODIMENTS

FIGS. 1 a-1 b schematically illustrate a first embodiment of afloorboard according to the invention. In FIGS. 1 a-1 b, the floorboardis shown to be provided with a mechanical locking system, which has-atongue 23 and a groove 20 for locking in the vertical direction.Moreover, the locking system comprises a projecting strip 21 extendingunder the neighbouring floorboard 1′ and supporting a locking element22, which cooperates with a downwardly open locking groove 24 in theneighbouring floorboard 1′. The mechanical locking system shown in FIGS.1 a and 1 b can be of the type as disclosed in WO 94/26999 or WO99/66151. However, it will be appreciated that other locking system mayalso be used. The edge portions shown in FIGS. 1 a-1 b can be long sides25 a, 25 b or short sides 26 a, 26 b of a floorboard 1.

A resilient base 10 is arranged on the underside of the floorboard 1shown in FIGS. 1 a and 1 b. The resilient base 10 gives the sports floorresilience and an impact-absorbing capability. The resilient base 10 isarranged on the floorboard, i.e. it is mounted on the floorboard inconnection with manufacture at the factory.

Moreover, an inner part L1 of the locking system, seen from the jointplane F, and outer part L2 of the locking system, seen from the jointplane F, are defined in FIGS. 1 a-1 b. The inner part L1 of the lockingsystem is the part where the locking system ends, seen from the jointplane F and inwards to the floorboard, i.e. the part where thefloorboard becomes homogeneous. The outer part L2 of the locking systemis the part where the locking system ends, seen from the joint plane andoutwards from the floorboard. It will be appreciated that even if L1 andL2 in FIG. 2 are defined based on the left floorboard 1, they can alsobe defined based on the right floorboard 1′.

According to one embodiment of the invention, the resilient base 10 mayextend outside the joint plane F, as is the case with the leftfloorboard 1 in FIG. 1 a. Correspondingly, the resilient base 10′ of theright floorboard 1′ in FIG. 1 a can be retracted relative to the jointplane F for the purpose of allowing joining of the floorboards 1, 1′.

According to another embodiment, the resilient base 10 of the leftfloorboard 1 can extend also beyond the outer-part L2 of the lockingsystem, which is shown in FIG. 1 a. The resilient base 10′ of the rightfloorboard 1′ can in this case be retracted to a corresponding, orgreater, extent. It will be appreciated that the projecting part of theresilient base can also be arranged on the right floorboard in FIG. 1.

According to one more embodiment, the resilient base 10 can extend sofar under the neighbouring floorboard (in the joined state) that thecore of the neighbouring floorboard will rest on the resilient base.

The sports floor which is made by means of the described floorboard 1 isarranged in such a manner that a joint between two floorboards rests ona resilient base which extends under the two floorboards.

It will be appreciated that the resilient base 10 can be arranged so asto extend beyond the joint plane F on the long side as well as on theshort side of the floorboard. Just as the design of the locking systemmay differ between the long side and the short side, also the extent ofthe resilient base 10 may differ between the short side and the longside. For example, the resilient base may extend further beyond thejoint plane on the short side than it does on the long side, but theopposite is also possible.

Further the resilient base 10 can be arranged so as to extendcontinuously along substantially the entire length of the edge of thefloorboard 1 as shown in FIG. 3 a. By “substantially” is here meant thatthe resilient base can deviate somewhat from the length of the edge ofthe floorboard. Moreover, for instance the length of the resilient basealong the long side of the floorboard can be designed so that the shortsides of the floorboard can be connected to short sides (or, in somecases, also long sides) of other floorboards 1′. Optionally, theresilient base can be arranged discontinuously, as a plurality ofseparated and spaced-apart resilient bases arranged along the edge. Anexample of this is shown regarding the short side of the floorboardshown in FIG. 3.

Furthermore the resilient base has an extent inwards from the edge ofthe floorboard 1, which extent can be selected to provide a floorboard 1with the desired resilience. In brief, the extent of the resilient baseon the underside of the floorboard, along the edges as well astransversely thereof, can be varied with a view to optimising both theresilience and the cost of the resilient base.

The material and thickness of the resilient base can be selected on thebasis of the application for which the floor is intended. Examples ofmaterials that may be used are expanded rubber or cellular plastics withopen or closed cells or equivalent elastic materials. In an embodimenttested by the Applicant, use is made of a resilient base of the type RG30, which is a cellular plastic resilient base of polyethylene, withclosed cells, and which is delivered by National Gummi AB, Halmstad,Sweden. It will be appreciated that the resilient base can be selectedamong a large number of different materials and thicknesses, dependingon the application.

With reference to FIGS. 2 a and 2 b, a second embodiment will now bedescribed. FIGS. 2 a and 2 b are detailed schematic cross-sectionalviews of two edges, provided with a mechanical locking system, of twoneighbouring floorboards 1, 1′, which are provided with a resilient base10 and a supporting layer 11 according to another embodiment of theinvention. In FIG. 2 a, the floorboards 1, 1′ are arranged next to eachother, and in FIG. 2 b they are joined together. The supporting layershown in FIGS. 2 a and 2 b can be arranged between the resilient baseand the underside of the floorboard (i.e. the under-side of thebalancing layer 4). The function of the supporting layer 11 is, interalia, to strengthen the locking system so that it will not be damagedwhen a joint is subjected to a load from above.

The supporting layer 11 can consist-of any material, such as MDF, HDF,plywood, particle board, wood, metal, such as aluminium, or plastic, andmay have any thickness. Alternatively, the supporting layer 11 and theresilient base 10 can be formed in one piece, for instance by that partof the resilient base that is to abut against the underside of thefloorboard being heat-treated, and optionally pressed, so that the cellstructure collapses and a more rigid layer forms, which layer can serveas a supporting layer.

According to one embodiment, the supporting layer 11 can be formed inone piece with the balancing layer 4. Also in this embodiment, thelocking system can be “disengaged” from the supporting layer, i.e. theprojecting part 21 of the locking system is not fixed to the balancinglayer/supporting layer.

According to one embodiment of the invention, the supporting layer canhave substantially the same extent as the resilient base 10.

It will also be appreciated that the extents of the supporting layer 11and the resilient base 10 can differ from each other. For instance, theentire floorboard can be provided with a supporting layer while theresilient layer is arranged only along the edges of the floorboard.

According to an embodiment tested by the Applicant, the resilient base10 and the supporting layer 11 have substantially the same extent andextend on the long side 16 mm outside the outer part L2 of the lockingsystem, and on the short side 40 mm outside the outer part L2 of thelocking system.

The resilient base 10 can be attached to the underside of the floorboard1, or to a part thereof by means of arbitrary fastening means. It ispossible to use, for instance, glue, rivets, staples, screws, oradhesive tape (double-stick). It is also possible to attach theresilient base to the floorboard by using thermal adhesion, i.e. byheating the material of the resilient base and/or the floorboard inorder to cause adhesion. In one embodiment, only part of the surface,facing the floorboard 1, of the resilient base 10 is provided withfastening means. Thus, for instance that part of the resilient base 10which extends beyond the inner part L1 of the locking system, or thatpart of the resilient base 10 which extends beyond the joint plane F canbe without fastening means, so that the locking system can operateindependently, or substantially independently, of the resilient base 10.

According to one embodiment, the supporting layer/resilient base isattached only under that part of the floorboard which does notconstitute the locking system.

What has been said above regarding the extent and fixing of theresilient base 10 to the floorboard thus also applies to the supportinglayer 11. Likewise the resilient base can be fixed to the supportinglayer 11 in one of the ways described with regard to the fixing of theresilient base to the floorboard.

FIG. 3 a is a perspective view of a floorboard 1 for a sports floor,which according to a third embodiment of the invention has a mechanicallocking system, a resilient base 11 and a supporting layer 10. As shownin FIGS. 3 a-3 c, the floorboard can be rectangular and thus have longsides 25 a, 25 b and short sides 26 a, 26 b.

The sports floor can be based on standard type floorboards 1, 1′, suchas those used for parquet floors, laminate floors or wooden floors. Suchfloorboards usually comprise a core 3 of, for instance, wood, woodslats, plywood, HDF, MDF, fibreboard or like materials. In someapplications, however, specially manufactured floorboards may bepreferable.

The upper side of the core 3 (FIGS. 1, 2) is provided with a surfacelayer 2 (FIGS. 1, 2), which serves to make the floorboard resistant towear, but also to give it an attractive appearance. In wood floors, thesurface layer 2 can be made of hardwood, such as oak or maple. Inlaminate floors, the surface layer may consist of a thin decorativelayer laminated with a transparent wear layer (not shown).

The underside of the core 3 (FIGS. 1, 2) can be provided with abalancing layer 4 (FIGS. 1, 2), whose primary function is to prevent thefloorboard from bending when the core 3 and the surface layer 2 areexpanded to different degrees, for instance owing to variations inmoisture content or temperature. The balancing layer 4 can be made of,for example, veneer, laminate film, plywood, HDF, MDF, particle board orlike materials.

Moreover, the floorboard shown in FIGS. 3 a-3 c has a mechanical lockingsystem of the type as described in, for example, WO 99/66151, whichallows joining of the floorboard 1 to neighbouring, identicalfloorboards 1′, so that neighbouring parts of the edge portions of thefloorboards 1, 1′ in the joined state define a joint plane F,perpendicular to the main plane P of the floorboards. The joined edgeportions of the long sides 25 a, 25 b define a first joint plane F1, andthe joined edge portions of the short sides 26 a, 26 b define a secondjoint plane F2.

Furthermore, the underside of the floorboard 1, along a long side 25 aand a short side 26 a, is provided with an impact-absorbing resilientbase 10 and a supporting layer 11 which extend beyond the respectivejoint planes F1, F2.

Along the long side 25 a of the floorboard, the edge portion is providedwith a band-like supporting layer 11, which extends on both sides of thejoint plane F1 and which extends beyond an outer part L2 (FIGS. 1 a, 2a) of the locking system. In the shown embodiment, the resilient base 10has on the long side substantially the same extent as the supportinglayer 11. According to the embodiment shown in FIGS. 3 a-3 c, the edgeportion of the opposite long side 25 b is not provided with a supportinglayer or resilient base.

The resilient base 10 on the underside of the floorboard 1 gives thesports floor resilience and a shock-absorbing capability. The resilientbase 10 is arranged on the floorboard, i.e. it is mounted on-thefloorboard in connection with manufacture thereof at the factory.

On the first short side 26 a, the edge portion is provided with aband-like supporting layer 11 which extends further beyond the jointplane F2 than do the supporting layer 11 and the resilient base 10 onthe edge portion of the long side 25 a. Moreover the resilient base onthis short side 26 a has an extent that corresponds to part of thesupporting layer 11.

The edge portion of the second short side 26 b has a supporting layer 11and, arranged thereon, a resilient base 10, which have a smaller extentthan the corresponding resilient base/supporting layer on the edgeportion of the first short side 26 a, and which do not extend beyond thejoint plane F2. In one embodiment, the supporting layer 11 and theresilient base 10 on this second short side 26 b can be arrangedcompletely-inside an inner part L1 (FIG. 1 a) of the locking system ofthe short side. Also in this case, the extent of the resilient base cancorrespond to only part of the extent of the supporting layer 11.Arranging a supporting layer/resilient base in this manner on the edgeportion of the second short side 26 b facilitates laying of the-floor bysupporting the floorboard 1 so that it lies flat and stable on the basebefore being joined to the other floorboards.

Optionally,.the resilient base can be arranged in a band-like portionalong the joint. Consequently, the resilient base need not extend overthe underside of the entire floorboard, which saves material and which,by the edge portions of the floorboards resting on the resilient base,gives the floorboards a greater degree of resilience, since under thatpart of the surface of the floorboards which is not provided with theresilient layer, they have a space between the base and the underside ofthe floorboard. According to the embodiment shown in FIG. 1, thisarrangement can be used on the long side as well as on the short side.

FIGS. 4 a-4 c illustrate different ways of arranging the resilient base10, 10 a, 10 b, 10 c and the supporting layer 11, 11 a, 11 b, 11 c onthe underside of a floorboard 1, 1′.

In FIG. 4 a, a resilient base 10 and optionally a supporting layer 11 ofsubstantially the same size as the floorboard 1, 1′ are arranged on theunderside thereof, so that the resilient base/the supporting layer isoffset in the longitudinal as well as the transverse direction of thefloorboard.

In FIG. 4 b, three resilient bases 10 a, 10 b, 10 c and optionally threesupporting layers 11 a, 11 b, 11 c are arranged on the underside of thefloorboard 1, 1′. First 10 a, 11 a, and second 10 b, 11 b resilientbases/supporting layers are arranged in the longitudinal direction ofthe floorboard 1, 1′, so that the first resilient base/supporting layer10 a, 11 a is arranged completely inside the edges of the floorboard,and the second resilient base/supporting layer 10 b, 11 b is arrangedalong one of the edges of the floorboard 1, 1′, so that the resilientbase/supporting layer extends beyond the joint plane F (not shown). Thethird resilient base/supporting layer is arranged to extend beyond thejoint plane on the short side of the floorboard and also beyond part ofthe joint plane of the long side.

In FIG. 4 c, two resilient bases/supporting surfaces 10 a, 10 b, 11 a,11 b are arranged in the longitudinal direction of the floorboard. Thefirst resilient base/supporting layer extends only beyond the jointplane of the short side, while the second resilient base/supportinglayer 10 b, 11 b extends beyond the joint plane of the short side aswell as the long side.

A space between the first and the second resilient bases/supportinglayers 10 a, 10 b; 11 a, 11 b as shown in

FIGS. 4 b and 4 c can be formed to modify the resilient function of thefloorboards. For instance, a wide space between two supporting layers orresilient bases can be used to give the floorboard better resilience.

FIG. 5 shows another way of arranging resilient bases 10, 10 a, 10 b, 10c and supporting layers 11, 11 a, 11 b, 11 c on the underside of afloorboard 1, 1′. In FIG. 5, a plurality of shorter resilientbases/supporting layers 10 d, 11 d are arranged so as to each extendbeyond the joint plane of the long side. At the short side of thefloorboard, a resilient base/supporting layer 10 c, 11 c is arranged toextend beyond the joint plane of the short side as well as the longside.

Also in the embodiment according to FIG. 5, a space between theresilient bases/supporting layers can be used to modify the resilientfunction of the floorboards.

It will be appreciated that width and length of each of the resilientbases/supporting layers 10, 10 a, 10 b, 10 c, 10 d; 11, 11 a, 11 b, 11c, 11 d can be selected to modify the resilient function of thefloorboards.

As described above, the floorboard can be provided with a locking systemfor joining the floorboards. A common variant of locking system is atongue-and-groove joint, which consists of a tongue which is insertedinto a groove and fixed therein by means of glue. In glue joints, thefloorboards are joined in the vertical direction D1 by means of thetongue and the groove, and in the horizontal direction D2 by means ofthe glue. When two floorboards 1, 1′ are joined along their edges, upperneighbouring parts 7, 7′ (FIGS. 1, 2) of edge portions 25 a, 25 b; 26 a,26 b of the floorboards define a joint plane F, which is vertical, i.e.perpendicular to the main plane P of the floorboards. In the case wherethe floorboard has locking systems on the long sides 25 a, 25 b as wellas the short sides 26 a, 26 b, first F1 and second. F2 joint planes aredefined, which can be orthogonal or substantially orthogonal to eachother.

As described above, there are also a plurality of mechanical lockingsystems, which are capable of joining floorboards without necessitatingthe use of glue. Thus, a mechanical locking system can mechanically jointhe floorboards both vertically D1 and horizontally D2. Such amechanical locking system has the advantage that the laying of the floorwill be speeded up while at the same time a durable flooring isobtained, without necessitating the use of glue. This may thus result inreduced use of glue, which may be advantageous from the environmentalpoint of view.

According to one embodiment, the floorboards according to the inventionare, along their long sides 25 a, 25 b and short sides 26 a, 26 b,provided with such a mechanical locking system. It will be appreciatedthat anyone of the known mechanical locking systems can be selected andthat the locking system on the short sides 26 a, 26 b need not be of thesame type or have the same composition of materials as the lockingsystem on the long sides 25 a, 25 b.

The floorboard can be manufactured or assembled by a floorboard ofprior-art type being provided with the resilient base 10 and optionallythe supporting layer 11. According to one embodiment, this is carriedout at the factory, and the floorboard is delivered with a resilientbase 10 and optionally a supporting layer 11. According to anotherembodiment, the floorboard and the resilient base are delivered in theform of a kit of parts, which U is joined before the installation of thesports floor. In such a kit of parts, the resilient base can be adjustedin advance in terms of shape and size to be mounted on thefloorboard-before laying thereof. Alternatively, the resilient base canbe delivered in bulk, for instance on a roll, and then, after cutting,be mounted on the floorboard.

If the kit comprises a supporting layer, this, and also the resilientbase, can be mounted on the floorboard, so that the floorboard isdelivered with the supporting layer mounted. In this case, the resilientbase can be-delivered separately as described above. Alternatively, alsothe supporting layer can be delivered separately, optionally adjusted interms of shape and size to be mounted on the floorboard before layingthereof.

It is also possible to provide a kit of parts, which comprises on theone hand a floorboard and, on the other hand, an assembly of supportinglayer and resilient base, in which case the assembly can be adjusted interms of shape and size to be mounted on the floorboard.

In the above-described embodiments of a kit of parts, the floorboard,the supporting layer and/or the resilient base can be provided withfastening means for joining to form a floorboard with the resilient baseand the supporting layer, if any, mounted. Such fastening meanscomprise, but are not limited to, glue, adhesive tape, screw means,rivets and other mechanical fastening means.

It will further be appreciated that the embodiments shown in FIGS. 4 a-cand FIG. 5 can be combined, and that it is possible to choose thelocation of the resilient bases according to one embodiment while at thesame time the supporting layer is located according to anotherembodiment. Other geometric shapes of the resilient base/supportinglayer are, of course, also conceivable. It will also be appreciated thatthe invention may be varied within the scope of the appended claims.

FIG. 6 shows another way in which the resilient base 10 b, 10 c and/orthe supporting layer 11 b, 11 c can be arranged on the underside of thefloorboard. In this embodiment, a first resilient base 10 b and/orsupporting layer 11 b is arranged on the long side of the floorboard insuch a manner that it extends beyond the joint plane F of the long sideand extends along substantially the entire length of the long side. Theextent of the resilient base inside the joint plane F can besubstantially smaller than the width of the floorboard, and in oneembodiment substantially smaller than half the width of the floorboard.In further embodiments, the extent inside the joint plane can be, forinstance, ⅓, ¼, ⅕ or ⅙ of the width of the floorboard. In still furtherembodiments, the extent can be from 1 cm up to 5 or 10 cm. The extentoutside the joint plane F can also be adjusted to what turns out to beconvenient. In one embodiment, the resilient base 10 b and/or thesupporting layer 11 b extends outside the outer part L2 of the lockingsystem. For instance, the extent can be between 0 and 10 cm from theouter part L2 of the locking system, but a greater extent is notexcluded, especially if large floorboards are used.

A second resilient base 10 c and/or supporting layer 11 c is arranged onthe short side of the floorboard and extends beyond the joint plane F ofthe short side and extends along substantially the entire length of theshort side. Regarding the extent inside and outside the joint plane ofthe short side, reference is made to that described with regard to thelong side.

It will be appreciated that the extent inside and outside the jointplane F of the short side and also the extent inside and outside thejoint plane F of the long side can be selected independently of eachother.

Besides, the resilient base 10 b, 10 c and/or the supporting layer 11 b,11 c in FIG. 6 can be arranged and fixed to the floorboard analogouslyto what has been described above with reference to FIGS. 1 and 2.

1. A floorboard for making a resilient floor by joining to at least oneneighbouring, substantially identical floorboard, so that joined upperneighbouring parts of the edge portions of the floorboards togetherdefine a joint plane, perpendicular to the main plane of the joinedfloorboards, the floorboard comprising: a resilient base, arranged onthe underside of the floorboard and extending beyond said joint plane, asupporting layer, arranged between an underside of the floorboard andthe resilient base, and a locking system, arranged along at least twoparallel edges of the floorboard and integrated with the floorboard, formechanical joining, vertically and horizontally, of the floorboard tothe neighbouring, substantially identical floorboard.
 2. A floorboard asclaimed in claim 1, wherein the resilient base is arranged so that, withthe floorboards in a joined state, it extends at least partly under theneighbouring, substantially identical floorboard.
 3. A floorboard asclaimed in claim 1, wherein the resilient base is made of an elasticmaterial.
 4. A floorboard as claimed in claim 3, wherein said elasticmaterial comprises at least one of expanded rubber and cellular plastic.5. A floorboard as claimed in claim 1, wherein the supporting layer hasa horizontal extent which is at least as great as a horizontal extent ofthe resilient base.
 6. A floorboard as claimed in claim 1, wherein thehorizontal extent of the supporting layer is smaller than a horizontalextent of the floorboard.
 7. A floorboard as claimed in claim 6, whereinthe horizontal extent of the supporting layer is less than half thehorizontal extent of the floorboard.
 8. A floorboard as claimed in claim1, wherein the supporting layer has a greater modulus of elasticity thanthe resilient base.
 9. A floorboard as claimed in claim 1, wherein thesupporting layer includes at least one of MDF, HDF, plywood, particleboard, wood material, plastic material and metal.
 10. A floorboard asclaimed in claim 1, wherein the resilient base extends beyond an outerpart (L2) of the locking system of the floorboard.
 11. A floorboard asclaimed in claim 1, wherein the long sides of the floorboard and theshort sides of the floorboard are provided with respectively first andsecond mechanical locking systems integrated with the floorboard, formechanical joining, vertically and horizontally, of the floorboard toneighbouring, substantially identical floorboards, so that joined upperneighbouring parts of the edge portions of the long sides and shortsides, respectively, together define first and second joint planes whichare perpendicular to the main plane of the joined floorboards, theresilient base at the edge portion of a short side and the edge portionof a long side extending beyond the respective joint planes.
 12. Afloorboard as claimed in claim 11, wherein the resilient base at theedge portion of the short side extends further beyond the first jointplane than beyond the second joint plane at the edge portion on the longside.
 13. A flooring for resilient floors, comprising a plurality offloorboards according to claim
 1. 14. A kit of parts for making aresilient floor, comprising: a floorboard for joining to a neighbouring,substantially identical floorboard, so that joined upper neighbouringparts of the edge portions of the floorboards together define a jointplane, which is perpendicular to the main plane (P) of the joinedfloorboards, a resilient base, which in terms of shape and size isadapted to be arranged on the underside of the floorboard, so that theresilient base extends beyond said joint plane, and a supporting layer,which in terms of size and shape is adapted to be arranged between saidfloorboard and said resilient base, the floorboard along at least twoparallel edges, being provided with a locking system integrated with thefloorboard, for mechanical joining, vertically and horizontally, of thefloorboard to the neighbouring, substantially identical floorboard. 15.A kit of parts as claimed in claim 14, wherein the resilient base isprovided with at least one fastening device, arranged on the undersideof the floorboard.
 16. A kit of parts as claimed in claim 14, whereinthe underside of the floorboard is provided with fastening means forarranging the resilient base.
 17. A kit of parts as claimed in claim 14,wherein the supporting layer is provided with at least one fasteningdevice, arranged between said floorboard and said resilient base.
 18. Akit of parts as claimed in claim 14, wherein said resilient base has afirst horizontal extent which is substantially equal to a length of afirst edge of the floorboard, and a second horizontal extent which isless than half a length of a second edge of the floorboards.
 19. Amethod for making a resilient floor by joining a floorboard to aneighbouring, substantially identical floorboard so that joined upperneighbouring parts of the edge portions on the floorboards togetherdefine a joint plane, which is perpendicular to the main plane of thejoined floorboards, the method comprising: joining the floorboards sothat a resilient base and a supporting layer, arranged on the undersideof the floorboard, extend beyond said joint plane, said joiningincluding mechanical joining, vertically and horizontally, of thefloorboard to the neighbouring, substantially identical floorboard. 20.A method for manufacturing a floorboard for making a resilient floor,comprising: providing a floorboard, designed for joining to aneighbouring, substantially identical floorboard, so that joined upperneighbouring parts of the edge portions of the floorboards togetherdefine a joint plane, which is perpendicular to the main plane of thejoined floorboards, arranging to the underside of the floorboard aresilient base, which extends beyond said joint plane, arranging asupporting layer between said floorboard and said resilient base, andarranging along at least two parallel edges of the floorboard a lockingsystem integrated with the floorboard, for mechanical joining,vertically and horizontally, of the floorboard to the neighbouring,substantially identical floorboard.